Firefighters, police and others who are the first on the scene in terrorist events should be better protected thanks to work at Pacific Northwest National Laboratory.

The Department of Energy national lab in Richland is the first to be accepted by the Department of Homeland Security to test and evaluate commercially available radiation detectors for a new program. The program is intended to help emergency response teams buy accurate and reliable radiation detectors.

That makes PNNL the first line of defense for emergency responders, said Michelle Johnson, project manager for PNNL's Ionizing Radiation Lab.

"We'll drive manufacturers to develop the best systems possible and look to PNNL to prove their performance," said Caroline Purdy, Department of Homeland Security program manager, in a statement.

Any agency buying radiation detectors using Department of Homeland Security grant money will use test results from the Graduated Radiation and Nuclear Detector Evaluation and Reporting, or GRaDER, program to choose systems that meet performance requirements.

And companies selling the systems to grant recipients must have them evaluated to get the equipment on GRaDER's list of evaluated equipment.

"The first responders are going to be the real winners because they are going to know what to expect and if the equipment suits their needs," said Scott Rogers, of Canberra Albuquerque, an Areva company that manufactures radiation detection instruments.

For those who depend on the radiation detectors, the question is often which works best in particular scenarios, said Al Conklin, a senior health physicist for the Washington State Department of Health.

PNNL will conduct a broad range of tests, using a suite of instruments and in some cases radiological material.

That includes testing the detectors in the chamber on the Hanford 300 Area nuclear reservation that once housed the High Temperature Lattice Test Reactor used to test nuclear fuel. Now the shielded area, with concrete walls up to 4 feet thick, makes an ideal place to use a neutron source to see how well instruments could detect a threat to emergency responders.

One of the toughest tests is making sure that equipment can detect radiation slightly above background levels very quickly - such as in the two seconds in which a user walks past a suspicious package, Johnson said.

Other tests make sure that environmental factors don't interfere with reliability or make the devices prone to false alarms.

In an environmental chamber, researchers can expose detectors to high heat and high humidity or cold air and see how well they hold up and how well they detect a radiological source in the chamber.

That not only will show how the detector performs in extreme weather conditions, but also in common situations such as when a detector is removed from a warm truck on a cold day, increasing the chance that condensation could form on the display panel.

"Customers need to know all the factors that can lead to failure," said scientist Phil Smith.

Detectors may be subjected to water to simulate being out in the rain, being dunked in a puddle or being dropped in salt water.

The detectors have to be able to continue operating even if they're clipped on belts next to cell phones or two-way radios. They can't emit an alarm if they're exposed to radiofrequency signals, such as those at some toll booths for drivers with rapid passes.

The detectors are subjected at the lab to electrostatic shock, and they're clamped on a vibrating table to make sure they can withstand the wear of being constantly carried in rigs such as fire trucks.

Not all of the tests are high tech, however. One of the tests for durability includes dropping devices to see if they break. Firefighters and other responders are in situations where the detectors get knocked around a lot, Rogers said.

"We start with the gentlest test first and work up," Johnson said. "The drop test is the last. Lots of equipment has gone back to the manufacturer in little body bags."

PNNL also tested a broad range of detectors in a program with Department of Homeland Security funds about five years ago to prepare a Consumer Reports-style publication as a guide to buying detectors. None of approximately 100 instruments passed the tests then.

But one thing that resulted from that testing was a chance to vet standards and set reasonable requirements, Johnson said.

Evaluations will start anew under standards that the Domestic Nuclear Detection Office of the Department of Homeland Security set which are partially based on standards of the American National Standards Institute. Vendors will pay the costs of having their radiation detection equipment evaluated.

National labs in Savannah River, S.C., and Oak Ridge, Tenn., also are applying for acceptance in the GRaDER program.